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Study of neutrino mass by long baseline neutrino oscillation experiment

Research Project

Project/Area Number 08101002
Research Category

Grant-in-Aid for Specially Promoted Research

Allocation TypeSingle-year Grants
Review Section Physics
Research InstitutionKYOTO UNIVERSITY (1999-2000)
The High Energy Accelerator Research Organization (1997-1998)
The University of Tokyo (1996)

Principal Investigator

NISHIKAWA Koichiro  Kyoto Univ., Physics, Prof., 大学院・理学研究科, 教授 (60198439)

Co-Investigator(Kenkyū-buntansha) ISHII Iakanobu  KEK, IPN, Res.Assoc, 素核研, 助手 (90134650)
OYAMA Yuichi  KEK.IPN, Res.Assc, 素核研, 助手 (30213896)
NAKAMURA Kenzo  KEK.IPN, Prof., 素核研, 教授 (10011735)
OKUNO Hideki  KEK IPN, Ass.Prof., 素核研, 助教授 (10013400)
Project Period (FY) 1996 – 2000
Project Status Completed (Fiscal Year 2000)
Budget Amount *help
¥288,000,000 (Direct Cost: ¥288,000,000)
Fiscal Year 2000: ¥5,000,000 (Direct Cost: ¥5,000,000)
Fiscal Year 1999: ¥5,000,000 (Direct Cost: ¥5,000,000)
Fiscal Year 1998: ¥80,000,000 (Direct Cost: ¥80,000,000)
Fiscal Year 1997: ¥127,000,000 (Direct Cost: ¥127,000,000)
Fiscal Year 1996: ¥71,000,000 (Direct Cost: ¥71,000,000)
KeywordsNeutrino mass / Neutrino oscillation / Accelerator neutrino / Long baseline / ニュートリノ / 素粒子 / レプトン / 標準模型 / 加速器ニュートリノ実験 / 陽子加速器
Research Abstract

The project was approved in 1996 to design and construct the near detector system for the long baseline neutrino oscillation experiment. This experiment uses Super-Kamiokande as a far detector. Neutrinos, predominantly muon neutrinos, are produced KEK proton synchrotron. The distance from KEK and Super-Kamiokande is 250km. The purpose is to test whether muon-neutrinos changes to other type of neutrinos in 250km travel to verify non-zero neutrino mass and lepton mixing. The events in the Super-Kamiokande are compared with those in near detector. In 1998 neutrino beam line and near detector construction were completed. In February 1999, we observed first neutrino event in near detector.
In June 1999, we identified first neutrino event in Super-Kamiokande. This is the first time in the world that man-made elementary particles traveled earth-scale distance and detected.
Until June 2000, we took data for 100 actual days. The data taking resumed in January 2001.
We have established that the pri … More nciples of long baseline neutrino oscillation experiment works and obtained the following results at its point.
(1) The direcdon of neutrino beam can be controlled and monitored within 1 mrad. during the entire period of the data taking. This directional precision is more than enough to predict the neutrino beam at 250km away.
(2) We can identify neutrino events in Super-Kamiokande with GPS time stamp. The backgrounds due to atmospheric neutrinos etc. are negligible at the level of 10^<-4>-10^<-5>.
(3) The events rate in the near detector system is about 3000/day. This rate is enough to monitor the stability of the neutrino beam.
(4) The result obtained during first 100 days of data taking is that we observed 27 events in Super-Kamiokande while we predict 40 events with an assumption of no oscillation. This equivalent to the statement that neutrino oscillation exists with 90% probability.
This result was reported at NEUTRINO-2000 in June and ICHEP (International Conference of High Energy Physics) in August 2000 and other conferences or workshops. With more data taking, we can firmly establish neutrino oscillation that is the proof that neutrinos are massive and lepton number is violated in nature. Less

Report

(6 results)
  • 2000 Annual Research Report   Final Research Report Summary
  • 1999 Annual Research Report
  • 1998 Annual Research Report
  • 1997 Annual Research Report
  • 1996 Annual Research Report
  • Research Products

    (29 results)

All Other

All Publications (29 results)

  • [Publications] K.Nishikawa and K2K collaboration: "Detection of Accelerator produced neutrinos at a distance of 250km"Phys.Lett.. (to be printed). (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nakamura and K2K collaboration: "status of K2K"Nucl.Phys.B (Proc.suppl.). 91. 203-209 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nakamura and K2K collaboration: "Status of K2K Long baseline experiment"Nucl.Phys.. A663. 795-798 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nishkawa et. al.: "Design construction, and operation of sciFa tracking detector for K2K"Nucl.Instrum.Meth.. A453. 165-176 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nishikawa and K2K collaboration: "Status of K2K (KEK to Kamioka long baseline neutrino oscillation experiment)"Nucl.Phys.B (Proc.suppl.). 77. 198-203 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nishikawa et.al.: "Test of beam monitoring equipment for a neutrino experiment"Beam Sci.Technol.. 3. 18-20 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nishikawa et. al.: "Soil shielding benchmark experiment and its simulation with MARS"Radiat.Prof.Dosim. 78. 305-331 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nishikawa et.al.: "Precision positioning of Super-Kamiokande with GPS for a long haseline neutrino experiment"Nucl.Instrum.Meth.. A398. 399-440 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nishikawa and K2K collaboration: "Detection of accelerator produced neutrinos at a distance of 250km"[hep-ex/0103001].

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nakamura and K2K Collaboration: "Status of K2K"Nucl.Phys.B (Proc.Supl). 91. 203-209 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nakamura and K2K Collaboration: "Status of the K2K long-baseline neutrino-oscillation experiment"Nucl.Phys.. A663&664. 795-798 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nishikawa et.al.K2K Collaboration: "Design, construction, and operation of SciFi tracking detector for K2K experiment."Nucl.Instrum.Meth.. A453. 165-176 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nishikawa.: "Status of K2K (KEK to kamioka long baseline neutrino oscillation experiment)."Nucl.Phys.B, Proc.Suppl. 77. 198-203 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nishikawa, et al.: "Tests of beam monitoring equipment for a neutrino experiment."Beam Sci.Technol.. 3. 18-22 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nishikawa, et al.: "Soil shielding benchmark experiment and its simulation with MARS using secondary particles produced by 12-GeV protons."Radiat.Prot.Dosim.. 78. 305-31 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] K.Nishikawa, et al.: "Precision positioning of Super Kamiokande with GPS for a long baseline neutrino oscillation experiment."Nucl.Instrum.Methods. A398. 399-40 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] A.Suzuki et al.: "Design, construction and operation of SciFi tracking detector for K2K experiment"Nucl.Instrum.Meth.. A453. 165-176 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] K. Nishikawa: "STATUS OF K2K (KEK TO KAMIOKA LONG BASELINE NEUTRINO OSCILLATION EXPERIMENT) Proceedings of 18th International Conference on Neutrino Physics and Astrophysics (NEUTRINO 98), Takayama, Japan 4-9, Jun. 1998"Nucl. Phys. Proc. Suppl.. 77. 198-203 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] M. Ieiri et al.: "NEUTRINO BEAM LINE FOR ALONG-BASELINE NEUTRINO OSCILLATION EXPERIMENT AT KEK, Proceedings 1st Asian Particle Accelerator Conference (APAC 98)"Proceedings 1st Asian Particle Accelerator Conference (APAC 98). 579-581 (1998)

    • Related Report
      1999 Annual Research Report
  • [Publications] J. E. Hill et al.: "TESTS OF BEAM MONITORING EQUIPMENT FOR A NEUTRINO EXPERIMENT"Beam Sci. Technol.. 3. 18-22 (1998)

    • Related Report
      1999 Annual Research Report
  • [Publications] T. Suzuki et al.: "SOIL SHIELDING BENCHMARK EXPERIMENT AND ITS SIMULATION WITH MARS USING SECONDARY PARTICLES PRODUCED BY 12-BEV PROTONS"Radiat. Prot. Dosim.. 78. 305-312 (1998)

    • Related Report
      1999 Annual Research Report
  • [Publications] Y. Yamanoi et al.: "LARGE HORN MAGNETS AT THE KEK NEUTRINO BEAM LINE"KEK-PREPRINT. Nov. 97-225. (1997)

    • Related Report
      1999 Annual Research Report
  • [Publications] H. Noumi et al.: "PRECISION POSITIONING OF SUPER KAMIOKANDE WITH GPS FOR A LONG BASELINE NEUTRINO OSCILLATION EXPERIMENT"Nucl. Instrum. Meth.. A398. 399-408 (1997)

    • Related Report
      1999 Annual Research Report
  • [Publications] J.Hill et al.: "Tests of Beam Monitoring Equipment fora Neutrino Experinat" Beam Sci.Technology. 3. 18-22 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] T.Suzuki et al.: "Soil shielding Benchmark Experinant and its simulation with MARS using secondary particies prcduced by 12GeV proton" Rediat.Prot.Dosim. 78. 305-312 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] H.Noumi: "Precision positioning of Super kamiokande with GPS for a long Baseline neutrino oscillation experiment" Nuclear Instrument and Method. A398. 399-408 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] Koichiro Nishikawa: "Present and future neutrino oscillation experiments in Japan" Proc.of the fourth KEK topical conference on flavor physics,Oct.29-31,1996.

    • Related Report
      1996 Annual Research Report
  • [Publications] Koichiro Nishikawa: "Present and Future neutrino experiments and high intensity proton accerators in Japan" Proc.of the 25th INS internat.symp.on nucl.and particle phys.with high-intensity proton accel.

    • Related Report
      1996 Annual Research Report
  • [Publications] Masayuki Etoh et.al.: "Scintillating fiber detector for KEK-PS E362" Tokai Univeristy bulletin 1996.

    • Related Report
      1996 Annual Research Report

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Published: 1996-04-01   Modified: 2018-03-28  

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